Hi Marek,
Seems this has caught a few others over the years, I found some references to images taken in 2005 with same "what's this object". Clearly my 30 second image burns that area out, often an issue when dealing with ellipticals. My searches focus on spirals. The object is real, shows well in a processed image I just got from Greg Bock below. The link below also shows it. Either way good pickup. Always get excited about the possibility.
http://www.astrophotos.net/pages/GAL...NGC%205363.htm
While position angle is useful a simple arrow next to an attached image with suspect more than suffices.
http://en.wikipedia.org/wiki/Position_angle
PeterM